UND astrophysicist shares in major astronomical discoveryPosted on 1/8/2013

Wayne Barkhouse, a University of North Dakota astrophysicist, recently shared in a major astronomical discovery that gets us a step closer to understanding how the universe works. This discovery is being hailed as a breakthrough in our understanding of the dynamics of the universe and offers a new glimpse into its origins.

Using a specially built camera high in the Chilean Andes, an international team of scientists called the Dark Energy Survey captured images of three very distant supernovae--exploding stars--that will help to prove that the universe is full of dark energy.

The proof of dark energy will be sought, in part, with software developed by Barkhouse, who's also an accomplished computer programmer.

"With the three supernovae observations we made with the Dark Energy Camera--the world's most powerful digital camera--we were using a technique that basically is like trying to determine the luminosity--the wattage--of a light bulb," said Barkhouse, an associate member of the Survey whose research interests include the study of galaxy clusters. "The question we're trying to answer with this research is why is the universe speeding up, instead of expanding at a decreasing rate the way Einstein's famous equation predicts it would."

Dark energy

The answer--to be measured precisely by the Dark Energy Survey--is that the universe is filled with dark energy which is helping to speed things up.

"The achievement of first light through the Dark Energy Camera begins a significant new era in our exploration of the Cosmic Frontier," said James Siegrist, DOE associate director of science for high-energy physics in a National Science Foundation story about the camera. "The results of this survey will bring us closer to understanding the mystery of dark energy and what it means for the universe."

The Dark Energy Camera was constructed at the U.S. Department of Energy's (DOE) Fermi National Accelerator Laboratory in Batavia, Ill., and mounted on the Victor M. Blanco telescope at the National Science Foundation's Cerro Tololo Inter-American Observatory in Chile, which is the southern branch of the U.S. National Optical Astronomy Observatory (NOAO). With this device, roughly the size of a phone booth, astronomers and physicists are probing the mystery of dark energy, the force they believe is causing the universe to expand faster and faster.

"The Dark Energy Survey will help us gather information about why the universe is accelerating, rather than slowing due to gravity," said Barkhouse, whose software is being used to analyze the vast quantities of data generated by the Dark Energy Camera.

According to the National Optical Astronomy Observatory. the Dark Energy Camera is the most powerful survey instrument of its kind, able to see light from over 100,000 galaxies up to 8 billion light years away in each snapshot. The camera's array of 62 charged-coupled devices has an unprecedented sensitivity to very red light, and along with the Blanco telescope's large light-gathering mirror (which spans 13 feet across), will allow scientists from around the world to pursue investigations ranging from studies of asteroids in our own solar system to the understanding of the origins and the fate of the universe.

Scientists collaborating in the Dark Energy Survey--including Barkhouse and his graduate student here at UND--will use the new camera to carry out the largest galaxy survey ever undertaken, and will use that data to carry out four probes of dark energy, studying galaxy clusters, supernovae, the large-scale clumping of galaxies and weak gravitational lensing. This will be the first time all four of these methods will be possible in a single experiment.

The Dark Energy Survey began in December, taking advantage of the atmospheric conditions in the Chilean Andes to deliver pictures with the sharpest resolution seen in such a wide-field astronomy survey. In just its first few nights of testing, the camera has already delivered images with excellent and nearly uniform spatial resolution.

Over five years, the survey will create detailed color images of one-eighth of the sky, or 5,000 square degrees, to discover and measure 300 million galaxies, 100,000 galaxy clusters and 4,000 supernovae.

Funding

The Dark Energy Survey is supported by funding from the U.S. Department of Energy Office of Science; the National Science Foundation; funding agencies in the United Kingdom, Spain, Brazil, Germany, and Switzerland; and the participating DES institutions.